Computer modeling of assembly of atoms in an electric field

A computer modeling of events that occurred under the scanning tunneling microscope (STM) tip was considered from a chemical standpoint. The DYQUAMOD, semiempirical dynamical-quantum chemical program system, which well manifested itself in a quantitative studying of nano-sized objects, was transformed into the DYQUAFIELD program system involving an external electrostatic field. The fields of changeable configurations were simulated by a set of up to 200 point charges. Atomic system modeling was focused on obtaining local electron density (LED) as well as on the object chemical transformations caused by the field. This article presents the results of simulating LED of differently originated graphite films, of a field action on a set of stable molecules, and of an irreversible in-field reconstruction of the diamondlike film surface, which demonstrates a possible nano-sized memory element creation. © 1996 John Wiley & Sons, Inc.